Protective headgear is used in many daily efforts to overlie and partly cover and shield one's head. This includes different types of protective headgear or helmets used for most sports, including specifically baseball batter's helmets, in-line skating helmets, hockey helmets, lacrosse helmets, as well as hard hats and work or construction helmets.
Such protective helmets commonly utilize a hard outer somewhat bowl-shaped shell sized sufficiently large to fit over the top and part of the sides of the user's head, and an inner padding or straping that fits snug against the head and holds the shell spaced from the head.
A major drawback of such headgear is improper fit of the helmet on the user's head, generally being too loose and allowing excessive helmet movement on the head. This is expected as standard sizes are available, and the intention is to have a selected standard size fit many different users, such as a single batter's helmet to be used only when actually batting.
Many helmets further have head band or strap arrangements inside of the shell and frequently inwardly of the padding to lie directly against the user's head. Minor size differences of the helmet needed for a firm or tight fit on the head frequently can be made by adjustment of the inner padding, head band or straping. However, such adjustments must be made from inside of the helmet, making such difficult to do, whereby it is typically not the practice of adjusting the helmet size when only a minor change is needed; instead, nor loose fits probably are the norm rather than the exception.